Ray Kroc is a salesman, who neglects his wife Ethel to travel around the country selling milkshake machines to cash-strapped diner owners. During a visit to San Bernardino in California, Ray takes a tour of the hamburger stand owned by Richard McDonald and his brother Maurice, who have perfected a lightning quick cooking system. Ray scents a lucrative business opportunity and persuades the siblings to sign a contract that allows him to franchise the McDonald's model around the country.

A mesmerising central performance from Michael Keaton enlivens John Lee Hancock's tasty biopic of the businessman whose ambition was a key ingredient in the birth of a fast food empire. Spanning a 16-year period, when the McDonald's brand name went from a single hexagonal stand run in California to a multi-million dollar global business defined by the iconic golden arches, The Founder documents a true story of greed and betrayal with a steady hand. It's a slow sizzle and director Hancock adopts a measured pace as his morally flawed central character sermonises fast food restaurants as "the new American church" at a time when drive-ins with servers on roller skates were the norm...

Robert D Siegel's script doesn't glorify the questionable ethics that defined this rise to greatness. Indeed, while we admire the businessman's gumption, his willingness to sacrifice good people in order to get what he wants - including a new wife - leaves a nasty taste in the mouth. Nice guys don't come first. Ray Kroc (Keaton) is a salesman, who neglects his wife Ethel (Laura Dern) to travel around the country selling milkshake machines to cash-strapped diner owners with the bold promise that if they "increase the supply, demand follows". His customers strongly disagree and Ray and trusty secretary June (Kate Kneeland) struggle to pay the bills.

During a visit to San Bernardino in California, Ray takes a tour of the hamburger stand owned by Richard McDonald (Nick Offerman) and his brother Maurice (John Carroll Lynch), who have perfected a lightning quick cooking system. "A fresh and delicious hamburger, grill to counter in 30 seconds," beams Maurice. Ray scents a lucrative business opportunity and persuades the siblings to sign a contract that allows him to franchise the McDonald's model around the country. At first, the arrangement works well and Ray attracts numerous franchise owners including Minnesota restaurateur Rollie Smith (Patrick Wilson) and his alluring wife Joan (Linda Cardellini). However, the contract terms prevent Ray from tampering with menu items, so he joins forces with slippery financial consultant Harry Sonneborn (BJ Novak) to wriggle through legal loopholes. "There's a wolf in the henhouse, and we let him in!" bellows Richard as Ray seizes control of their brand name.

The Founder pivots around Keaton, who stares unflinchingly into the camera for scenes that bookend the film, willing us to believe his smooth patter. It's a bravura portrayal of a deeply flawed man, who put profits ahead of personal relationships and made himself - and the people closest to him - obscenely rich. Offerman and Lynch capture our exasperation as the brothers' efforts to maintain control of their brand are undermined by Kroc's underhand manoeuvres. "Persistence and determination alone are all-powerful," declares Ray. Those words at least ring true.